Tobacco cultivation has no adverse impacts on soil fertility: study

A joint study by the University of Peradeniya Soil Science Department and Agriculture Faculty has refuted claims that tobacco causes soil fertility degradation.

The results of this study were presented at the recently concluded fourth International Conference on Agriculture and Forestry, organised by the International Institute of Knowledge Management.

The study was conducted in the Galewela region by the university to determine the impacts of incorporating tobacco on soil during rice-based crop rotation. This follows allegations by vested groups that tobacco cultivation causes widespread soil erosion and degradation in the country and beyond. Whilst there exists little or no scientific evidence to validate these claims, the findings of this new study by the University of Peradeniya lend further evidence that tobacco causes no harm to soil quality. This latest study was conducted over three crop-rotation cycles, as tobacco-paddy-tobacco, tobacco-paddy-other (vegetables, fallow, field crops) and other-paddy-other. Whilst the wet aggregate stability was greater than 50 percent, it found that incorporating tobacco did not cause any instability in the studied soils. Cultivating tobacco has in fact increased the soil’s organic carbon and its cation exchange capacity, providing a buffer against soil acidification, whilst also improving phosphorus, calcium, zinc and copper content, which is beneficial for agriculture and soil fertility.

There are around 20,000 tobacco farmer families involved in the cultivation of tobacco known to support over 300,000 livelihoods over across the island while infusing nearly Rs.2 billion into the rural economy annually.